GeForce GTX 275 vs Radeon HD 4890 2GB

Intro

Compare those specifications to the Radeon HD 4890 2GB, which has a core clock speed of 1000 MHz and a GDDR5 memory frequency of 975 MHz. It also features a 256-bit memory bus, and makes use of a 55 nm design. It features 800(160x5) SPUs, 40 TAUs, and 16 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4890 2GB		190 Watts
GeForce GTX 275		219 Watts
	Difference: 29 Watts (15%)

Memory Bandwidth

Theoretically speaking, the GeForce GTX 275 should perform a little bit faster than the Radeon HD 4890 2GB in general. (explain)

GeForce GTX 275		127008 MB/sec
Radeon HD 4890 2GB		124800 MB/sec
	Difference: 2208 (2%)

Texel Rate

The GeForce GTX 275 is a lot (approximately 27%) more effective at AF than the Radeon HD 4890 2GB. (explain)

GeForce GTX 275		50640 Mtexels/sec
Radeon HD 4890 2GB		40000 Mtexels/sec
	Difference: 10640 (27%)

Pixel Rate

The GeForce GTX 275 should be a bit (more or less 11%) faster with regards to AA than the Radeon HD 4890 2GB, and also able to handle higher resolutions better. (explain)

GeForce GTX 275		17724 Mpixels/sec
Radeon HD 4890 2GB		16000 Mpixels/sec
	Difference: 1724 (11%)

Please note that the above 'benchmarks' are all just theoretical - the results were calculated based on the card's specifications, and real-world performance may (and probably will) vary at least a bit.

Price Comparison

Specifications

Memory Bandwidth: Bandwidth is the max amount of information (measured in MB per second) that can be transferred across the external memory interface within a second. It is worked out by multiplying the card's bus width by its memory speed. In the case of DDR type RAM, it should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are processed in one second. This number is calculated by multiplying the total amount of texture units of the card by the core speed of the chip. The higher the texel rate, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

Pixel Rate: Pixel rate is the maximum number of pixels the video card could possibly write to the local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the amount of Render Output Units by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on quite a few other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.